1. Technical Field
The present disclosure relates to an optical image capturing system. More particularly, the present disclosure relates to a miniaturized optical image capturing system applicable to portable electronic products.
2. Description of Related Art
In recent years, with the popularity of mobile products having camera functionalities, a demand for optical system has been increasing. A photosensitive sensor of a conventional optical system is typically a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. As the advanced semiconductor manufacturing technologies have allowed a pixel size of sensors to be reduced and the optical systems have gradually evolved toward a field of higher megapixels, there is an increasing demand for better image quality.
A conventional optical system employed in a portable electronic product, as shown in the U.S. Pat. No. 8,169,528, mainly adopts a structure of four lens elements. Due to the popularity of mobile products with high-end specifications, such as smart phones and PDAs (Personal Digital Assistants), requirements of higher megapixels and better image quality have been increasing rapidly. However, the conventional optical systems cannot satisfy the requirements of high-end optical systems with camera functionalities.
On the other hand, the third lens element together with the fourth lens element of a conventional optical system having five lens elements is often not arranged well; therefore, it is not favorable for correcting the astigmatism. Moreover, the total track length of the conventional optical system with five lens elements is too long; therefore, it results in poor image quality.
Accordingly, there is an increasing demand for compact optical lens systems featuring good astigmatism correction ability and better image quality.